Marcellus
From Conservapedia
Marcellus (42 B.C. to 23 B.C.) was the son of Octavia sister of Augustus, the first Emperor of Rome. Augustus, having no male heirs of his own, was very fond of his nephew and was seen often with him in public. He even had him marry his only child, his daughter Julia. Beloved by the people of Rome, his future looked bright, but he fell ill and died at the age of 19. History has recorded that Livia, Augustus' wife, saw to his premature end so she could clear the way for her son Tiberius to become Emperor after the death of Augustus.